Stop PKCS7_verify() core dumping with unknown public

[thirdparty/openssl.git] / CHANGES

 OpenSSL CHANGES
 _______________

 Changes between 0.9.6 and 0.9.7  [xx XXX 2000]

  *) Avoid coredump with unsupported or invalid public keys by checking if
     X509_get_pubkey() fails in PKCS7_verify(). Fix memory leak when
     PKCS7_verify() fails with non detached data.
     [Steve Henson]

  *) Change OCSP_cert_to_id() to tolerate a NULL subject certificate and
     OCSP_cert_id_new() a NULL serialNumber. This allows a partial certificate
     ID to be generated from the issuer certificate alone which can then be
     passed to OCSP_id_issuer_cmp().
     [Steve Henson]

  *) New compilation option ASN1_ITEM_FUNCTIONS. This causes the new
     ASN1 modules to export functions returning ASN1_ITEM pointers
     instead of the ASN1_ITEM structures themselves. This adds several
     new macros which allow the underlying ASN1 function/structure to
     be accessed transparently. As a result code should not use ASN1_ITEM
     references directly (such as &X509_it) but instead use the relevant
     macros (such as ASN1_ITEM_rptr(X509)). This option is to allow
     use of the new ASN1 code on platforms where exporting structures
     is problematical (for example in shared libraries) but exporting
     functions returning pointers to structures is not.
     [Steve Henson]

  *) Add support for overriding the generation of SSL/TLS session IDs.
     These callbacks can be registered either in an SSL_CTX or per SSL.
     The purpose of this is to allow applications to control, if they wish,
     the arbitrary values chosen for use as session IDs, particularly as it
     can be useful for session caching in multiple-server environments. A
     command-line switch for testing this (and any client code that wishes
     to use such a feature) has been added to "s_server".
     [Geoff Thorpe, Lutz Jaenicke]

  *) Modify mkdef.pl to recognise and parse prprocessor conditionals
     of the form '#if defined(...) || defined(...) || ...' and
     '#if !defined(...) && !defined(...) && ...'.  This also avoids
     the growing number of special cases it was previously handling.
     [Richard Levitte]

  *) Don't use getenv in library functions when run as setuid/setgid.
     New function OPENSSL_issetugid().
     [Ulf Moeller]

  *) Make all configuration macros available for application by making
     sure they are available in opensslconf.h, by giving them names starting
     with "OPENSSL_" to avoid conflicts with other packages and by making
     sure e_os2.h will cover all platform-specific cases together with
     opensslconf.h.
     Additionally, it is now possible to define configuration/platform-
     specific names (called "system identities").  In the C code, these
     are prefixed with "OPENSSL_SYSNAME_".  e_os2.h will create another
     macro with the name beginning with "OPENSSL_SYS_", which is determined
     from "OPENSSL_SYSNAME_*" or compiler-specific macros depending on
     what is available.
     [Richard Levitte]

  *) New option -set_serial to 'req' and 'x509' this allows the serial
     number to use to be specified on the command line. Previously self
     signed certificates were hard coded with serial number 0 and the 
     CA options of 'x509' had to use a serial number in a file which was
     auto incremented.
     [Steve Henson]

  *) Avoid false positives in memory leak detection code (crypto/mem_dbg.c)
     due to incorrect handling of multi-threading:

     1. Fix timing glitch in the MemCheck_off() portion of CRYPTO_mem_ctrl().

     2. Fix logical glitch in is_MemCheck_on() aka CRYPTO_is_mem_check_on().

     3. Count how many times MemCheck_off() has been called so that
        nested use can be treated correctly.  This also avoids 
        inband-signalling in the previous code (which relied on the
        assumption that thread ID 0 is impossible).
     [Bodo Moeller]

  *) New options to 'ca' utility to support V2 CRL entry extensions.
     Currently CRL reason, invalidity date and hold instruction are
     supported. Add new CRL extensions to V3 code and some new objects.
     [Steve Henson]

  *) Add "-rand" option also to s_client and s_server.
     [Lutz Jaenicke]

  *) New function EVP_CIPHER_CTX_set_padding() this is used to
     disable standard block padding (aka PKCS#5 padding) in the EVP
     API, which was previously mandatory. This means that the data is
     not padded in any way and so the total length much be a multiple
     of the block size, otherwise an error occurs.
     [Steve Henson]

  *) Initial (incomplete) OCSP SSL support.
     [Steve Henson]

  *) Fix CPU detection on Irix 6.x.
     [Kurt Hockenbury <khockenb@stevens-tech.edu> and
      "Bruce W. Forsberg" <bruce.forsberg@baesystems.com>]

  *) New function OCSP_parse_url(). This splits up a URL into its host,
     port and path components: primarily to parse OCSP URLs. New -url
     option to ocsp utility.
     [Steve Henson]

  *) New nonce behavior. The return value of OCSP_check_nonce() now 
     reflects the various checks performed. Applications can decide
     whether to tolerate certain situations such as an absent nonce
     in a response when one was present in a request: the ocsp application
     just prints out a warning. New function OCSP_add1_basic_nonce()
     this is to allow responders to include a nonce in a response even if
     the request is nonce-less.
     [Steve Henson]

  *) Use the cached encoding of an X509_NAME structure rather than
     copying it. This is apparently the reason for the libsafe "errors"
     but the code is actually correct.
     [Steve Henson]

  *) Disable stdin buffering in load_cert (apps/apps.c) so that no certs are
     skipped when using openssl x509 multiple times on a single input file,
     e.g. "(openssl x509 -out cert1; openssl x509 -out cert2) <certs".
     [Bodo Moeller]

  *) Make ASN1_UTCTIME_set_string() and ASN1_GENERALIZEDTIME_set_string()
     set string type: to handle setting ASN1_TIME structures. Fix ca
     utility to correctly initialize revocation date of CRLs.
     [Steve Henson]

  *) New option SSL_OP_CIPHER_SERVER_PREFERENCE allows the server to override
     the clients preferred ciphersuites and rather use its own preferences.
     Should help to work around M$ SGC (Server Gated Cryptography) bug in
     Internet Explorer by ensuring unchanged hash method during stepup.
     [Lutz Jaenicke]

  *) Make mkdef.pl recognise all DECLARE_ASN1 macros, change rijndael
     to aes and add a new 'exist' option to print out symbols that don't
     appear to exist.
     [Steve Henson]

  *) Additional options to ocsp utility to allow flags to be set and
     additional certificates supplied.
     [Steve Henson]

  *) Add the option -VAfile to 'openssl ocsp', so the user can give the
     OCSP client a number of certificate to only verify the response
     signature against.
     [Richard Levitte]

  *) Add new function BN_rand_range(), and fix DSA_sign_setup() to prevent
     Bleichenbacher's DSA attack.
     Extend BN_[pseudo_]rand: As before, top=1 forces the highest two bits
     to be set and top=0 forces the highest bit to be set; top=-1 is new
     and leaves the highest bit random.
     [Ulf Moeller, Bodo Moeller]

  *) Update Rijndael code to version 3.0 and change EVP AES ciphers to
     handle the new API. Currently only ECB, CBC modes supported. Add new
     AES OIDs. Add TLS AES ciphersuites as described in the "AES Ciphersuites
     for TLS" draft-ietf-tls-ciphersuite-03.txt.
     [Ben Laurie, Steve Henson]

  *) In the NCONF_...-based implementations for CONF_... queries
     (crypto/conf/conf_lib.c), if the input LHASH is NULL, avoid using
     a temporary CONF structure with the data component set to NULL
     (which gives segmentation faults in lh_retrieve).
     Instead, use NULL for the CONF pointer in CONF_get_string and
     CONF_get_number (which may use environment variables) and directly
     return NULL from CONF_get_section.
     [Bodo Moeller]

  *) Fix potential buffer overrun for EBCDIC.
     [Ulf Moeller]

  *) New function OCSP_copy_nonce() to copy nonce value (if present) from
     request to response.
     [Steve Henson]

  *) Functions for OCSP responders. OCSP_request_onereq_count(),
     OCSP_request_onereq_get0(), OCSP_onereq_get0_id() and OCSP_id_get0_info()
     extract information from a certificate request. OCSP_response_create()
     creates a response and optionally adds a basic response structure.
     OCSP_basic_add1_status() adds a complete single response to a basic
     reponse and returns the OCSP_SINGLERESP structure just added (to allow
     extensions to be included for example). OCSP_basic_add1_cert() adds a
     certificate to a basic response and OCSP_basic_sign() signs a basic
     response with various flags. New helper functions ASN1_TIME_check()
     (checks validity of ASN1_TIME structure) and ASN1_TIME_to_generalizedtime()
     (converts ASN1_TIME to GeneralizedTime).
     [Steve Henson]

  *) Various new functions. EVP_Digest() combines EVP_Digest{Init,Update,Final}()
     in a single operation. X509_get0_pubkey_bitstr() extracts the public_key
     structure from a certificate. X509_pubkey_digest() digests tha public_key
     contents: this is used in various key identifiers. 
     [Steve Henson]

  *) Tolerate nonRepudiation as being valid for S/MIME signing and certSign
     keyUsage if basicConstraints absent for a CA.
     [Steve Henson]

  *) Make SMIME_write_PKCS7() write mail header values with a format that
     is more generally accepted (no spaces before the semicolon), since
     some programs can't parse those values properly otherwise.  Also make
     sure BIO's that break lines after each write do not create invalid
     headers.
     [Richard Levitte]

  *) Make sk_sort() tolerate a NULL argument.
     [Steve Henson reported by Massimiliano Pala <madwolf@comune.modena.it>]

  *) New OCSP verify flag OCSP_TRUSTOTHER. When set the "other" certificates
     passed by the function are trusted implicitly. If any of them signed the
     reponse then it is assumed to be valid and is not verified.
     [Steve Henson]

  *) Zero the premaster secret after deriving the master secret in
     DH ciphersuites.
     [Steve Henson]

  *) In PKCS7_set_type() initialise content_type in PKCS7_ENC_CONTENT
     to data. This was previously part of the PKCS7 ASN1 code. This
     was causing problems with OpenSSL created PKCS#12 and PKCS#7 structures.
     [Steve Henson, reported by Kenneth R. Robinette
				<support@securenetterm.com>]

  *) Add CRYPTO_push_info() and CRYPTO_pop_info() calls to new ASN1
     routines: without these tracing memory leaks is very painful.
     Fix leaks in PKCS12 and PKCS7 routines.
     [Steve Henson]

  *) Fix for Irix with NO_ASM.
     ["Bruce W. Forsberg" <bruce.forsberg@baesystems.com>]

  *) Add some EVP_add_digest_alias registrations (as found in
     OpenSSL_add_all_digests()), to SSL_library_init()
     aka OpenSSL_add_ssl_algorithms().  This provides improved
     compatibility with peers using X.509 certificates
     with unconventional AlgorithmIdentifier OIDs.
     [Bodo Moeller]

  *) ./config script fixes.
     [Ulf Moeller, Richard Levitte]

  *) Make X509_time_adj() cope with the new behaviour of ASN1_TIME_new().
     Previously it initialised the 'type' argument to V_ASN1_UTCTIME which
     effectively meant GeneralizedTime would never be used. Now it
     is initialised to -1 but X509_time_adj() now has to check the value
     and use ASN1_TIME_set() if the value is not V_ASN1_UTCTIME or
     V_ASN1_GENERALIZEDTIME, without this it always uses GeneralizedTime.
     [Steve Henson, reported by Kenneth R. Robinette
				<support@securenetterm.com>]

  *) Fixes to BN_to_ASN1_INTEGER when bn is zero. This would previously
     result in a zero length in the ASN1_INTEGER structure which was
     not consistent with the structure when d2i_ASN1_INTEGER() was used
     and would cause ASN1_INTEGER_cmp() to fail. Enhance s2i_ASN1_INTEGER()
     to cope with hex and negative integers. Fix bug in i2a_ASN1_INTEGER()
     where it did not print out a minus for negative ASN1_INTEGER.
     [Steve Henson]

  *) Fix 'openssl passwd -1'.
     [Bodo Moeller]

  *) Add summary printout to ocsp utility. The various functions which
     convert status values to strings have been renamed to:
     OCSP_response_status_str(), OCSP_cert_status_str() and
     OCSP_crl_reason_str() and are no longer static. New options
     to verify nonce values and to disable verification. OCSP response
     printout format cleaned up.
     [Steve Henson]

  *) Add additional OCSP certificate checks. These are those specified
     in RFC2560. This consists of two separate checks: the CA of the
     certificate being checked must either be the OCSP signer certificate
     or the issuer of the OCSP signer certificate. In the latter case the
     OCSP signer certificate must contain the OCSP signing extended key
     usage. This check is performed by attempting to match the OCSP
     signer or the OCSP signer CA to the issuerNameHash and issuerKeyHash
     in the OCSP_CERTID structures of the response.
     [Steve Henson]

  *) Initial OCSP certificate verification added to OCSP_basic_verify()
     and related routines. This uses the standard OpenSSL certificate
     verify routines to perform initial checks (just CA validity) and
     to obtain the certificate chain. Then additional checks will be
     performed on the chain. Currently the root CA is checked to see
     if it is explicitly trusted for OCSP signing. This is used to set
     a root CA as a global signing root: that is any certificate that
     chains to that CA is an acceptable OCSP signing certificate.
     [Steve Henson]

  *) New '-extfile ...' option to 'openssl ca' for reading X.509v3
     extensions from a separate configuration file.
     As when reading extensions from the main configuration file,
     the '-extensions ...' option may be used for specifying the
     section to use.
     [Massimiliano Pala <madwolf@comune.modena.it>]

  *) Change PKCS12_key_gen_asc() so it can cope with non null
     terminated strings whose length is passed in the passlen
     parameter, for example from PEM callbacks. This was done
     by adding an extra length parameter to asc2uni().
     [Steve Henson, reported by <oddissey@samsung.co.kr>]

  *) New OCSP utility. Allows OCSP requests to be generated or
     read. The request can be sent to a responder and the output
     parsed, outputed or printed in text form. Not complete yet:
     still needs to check the OCSP response validity.
     [Steve Henson]

  *) New subcommands for 'openssl ca':
     'openssl ca -status <serial>' prints the status of the cert with
     the given serial number (according to the index file).
     'openssl ca -updatedb' updates the expiry status of certificates
     in the index file.
     [Massimiliano Pala <madwolf@comune.modena.it>]

  *) New '-newreq-nodes' command option to CA.pl.  This is like
     '-newreq', but calls 'openssl req' with the '-nodes' option
     so that the resulting key is not encrypted.
     [Damien Miller <djm@mindrot.org>]

  *) New configuration for the GNU Hurd.
     [Jonathan Bartlett <johnnyb@wolfram.com> via Richard Levitte]

  *) Initial code to implement OCSP basic response verify. This
     is currently incomplete. Currently just finds the signer's
     certificate and verifies the signature on the response.
     [Steve Henson]

  *) New SSLeay_version code SSLEAY_DIR to determine the compiled-in
     value of OPENSSLDIR.  This is available via the new '-d' option
     to 'openssl version', and is also included in 'openssl version -a'.
     [Bodo Moeller]

  *) Fix C code generated by 'openssl dsaparam -C': If a BN_bin2bn
     call failed, free the DSA structure.
     [Bodo Moeller]

  *) Allowing defining memory allocation callbacks that will be given
     file name and line number information in additional arguments
     (a const char* and an int).  The basic functionality remains, as
     well as the original possibility to just replace malloc(),
     realloc() and free() by functions that do not know about these
     additional arguments.  To register and find out the current
     settings for extended allocation functions, the following
     functions are provided:

	CRYPTO_set_mem_ex_functions
	CRYPTO_set_locked_mem_ex_functions
	CRYPTO_get_mem_ex_functions
	CRYPTO_get_locked_mem_ex_functions

     These work the same way as CRYPTO_set_mem_functions and friends.
     CRYPTO_get_[locked_]mem_functions now writes 0 where such an
     extended allocation function is enabled.
     Similarly, CRYPTO_get_[locked_]mem_ex_functions writes 0 where
     a conventional allocation function is enabled.
     [Richard Levitte, Bodo Moeller]

  *) Fix to uni2asc() to cope with zero length Unicode strings.
     These are present in some PKCS#12 files.
     [Steve Henson]

  *) Finish off removing the remaining LHASH function pointer casts.
     There should no longer be any prototype-casting required when using
     the LHASH abstraction, and any casts that remain are "bugs". See
     the callback types and macros at the head of lhash.h for details
     (and "OBJ_cleanup" in crypto/objects/obj_dat.c as an example).
     [Geoff Thorpe]

  *) Add automatic query of EGD sockets in RAND_poll() for the unix variant.
     If an EGD or PRNGD is running and enough entropy is returned, automatic
     seeding like with /dev/[u]random will be performed.
     Positions tried are: /etc/entropy, /var/run/egd-pool.
     [Lutz Jaenicke]

  *) Change the Unix RAND_poll() variant to be able to poll several
     random devices, as specified by DEVRANDOM, until a sufficient amount
     of data has been collected.   We spend at most 10 ms on each file
     (select timeout) and read in non-blocking mode.  DEVRANDOM now
     defaults to the list "/dev/urandom", "/dev/random", "/dev/srandom"
     (previously it was just the string "/dev/urandom"), so on typical
     platforms the 10 ms delay will never occur.
     Also separate out the Unix variant to its own file, rand_unix.c.
     For VMS, there's a currently-empty rand_vms.c.
     [Richard Levitte]

  *) Move OCSP client related routines to ocsp_cl.c. These
     provide utility functions which an application needing
     to issue a request to an OCSP responder and analyse the
     response will typically need: as opposed to those which an
     OCSP responder itself would need which will be added later.

     OCSP_request_sign() signs an OCSP request with an API similar
     to PKCS7_sign(). OCSP_response_status() returns status of OCSP
     response. OCSP_response_get1_basic() extracts basic response
     from response. OCSP_resp_find_status(): finds and extracts status
     information from an OCSP_CERTID structure (which will be created
     when the request structure is built). These are built from lower
     level functions which work on OCSP_SINGLERESP structures but
     wont normally be used unless the application wishes to examine
     extensions in the OCSP response for example.

     Replace nonce routines with a pair of functions.
     OCSP_request_add1_nonce() adds a nonce value and optionally
     generates a random value. OCSP_check_nonce() checks the
     validity of the nonce in an OCSP response.
     [Steve Henson]

  *) Change function OCSP_request_add() to OCSP_request_add0_id().
     This doesn't copy the supplied OCSP_CERTID and avoids the
     need to free up the newly created id. Change return type
     to OCSP_ONEREQ to return the internal OCSP_ONEREQ structure.
     This can then be used to add extensions to the request.
     Deleted OCSP_request_new(), since most of its functionality
     is now in OCSP_REQUEST_new() (and the case insensitive name
     clash) apart from the ability to set the request name which
     will be added elsewhere.
     [Steve Henson]

  *) Update OCSP API. Remove obsolete extensions argument from
     various functions. Extensions are now handled using the new
     OCSP extension code. New simple OCSP HTTP function which 
     can be used to send requests and parse the response.
     [Steve Henson]

  *) Fix the PKCS#7 (S/MIME) code to work with new ASN1. Two new
     ASN1_ITEM structures help with sign and verify. PKCS7_ATTR_SIGN
     uses the special reorder version of SET OF to sort the attributes
     and reorder them to match the encoded order. This resolves a long
     standing problem: a verify on a PKCS7 structure just after signing
     it used to fail because the attribute order did not match the
     encoded order. PKCS7_ATTR_VERIFY does not reorder the attributes:
     it uses the received order. This is necessary to tolerate some broken
     software that does not order SET OF. This is handled by encoding
     as a SEQUENCE OF but using implicit tagging (with UNIVERSAL class)
     to produce the required SET OF.
     [Steve Henson]

  *) Have mk1mf.pl generate the macros OPENSSL_BUILD_SHLIBCRYPTO and
     OPENSSL_BUILD_SHLIBSSL and use them appropriately in the header
     files to get correct declarations of the ASN.1 item variables.
     [Richard Levitte]

  *) Rewrite of PKCS#12 code to use new ASN1 functionality. Replace many
     PKCS#12 macros with real functions. Fix two unrelated ASN1 bugs:
     asn1_check_tlen() would sometimes attempt to use 'ctx' when it was
     NULL and ASN1_TYPE was not dereferenced properly in asn1_ex_c2i().
     New ASN1 macro: DECLARE_ASN1_ITEM() which just declares the relevant
     ASN1_ITEM and no wrapper functions.
     [Steve Henson]

  *) New functions or ASN1_item_d2i_fp() and ASN1_item_d2i_bio(). These
     replace the old function pointer based I/O routines. Change most of
     the *_d2i_bio() and *_d2i_fp() functions to use these.
     [Steve Henson]

  *) Enhance mkdef.pl to be more accepting about spacing in C preprocessor
     lines, recognice more "algorithms" that can be deselected, and make
     it complain about algorithm deselection that isn't recognised.
     [Richard Levitte]

  *) New ASN1 functions to handle dup, sign, verify, digest, pack and
     unpack operations in terms of ASN1_ITEM. Modify existing wrappers
     to use new functions. Add NO_ASN1_OLD which can be set to remove
     some old style ASN1 functions: this can be used to determine if old
     code will still work when these eventually go away.
     [Steve Henson]

  *) New extension functions for OCSP structures, these follow the
     same conventions as certificates and CRLs.
     [Steve Henson]

  *) New function X509V3_add1_i2d(). This automatically encodes and
     adds an extension. Its behaviour can be customised with various
     flags to append, replace or delete. Various wrappers added for
     certifcates and CRLs.
     [Steve Henson]

  *) Fix to avoid calling the underlying ASN1 print routine when
     an extension cannot be parsed. Correct a typo in the
     OCSP_SERVICELOC extension. Tidy up print OCSP format.
     [Steve Henson]

  *) Increase s2->wbuf allocation by one byte in ssl2_new (ssl/s2_lib.c).
     Otherwise do_ssl_write (ssl/s2_pkt.c) will write beyond buffer limits
     when writing a 32767 byte record.
     [Bodo Moeller; problem reported by Eric Day <eday@concentric.net>]

  *) In RSA_eay_public_{en,ed}crypt and RSA_eay_mod_exp (rsa_eay.c),
     obtain lock CRYPTO_LOCK_RSA before setting rsa->_method_mod_{n,p,q}.

     (RSA objects have a reference count access to which is protected
     by CRYPTO_LOCK_RSA [see rsa_lib.c, s3_srvr.c, ssl_cert.c, ssl_rsa.c],
     so they are meant to be shared between threads.)
     [Bodo Moeller, Geoff Thorpe; original patch submitted by
     "Reddie, Steven" <Steven.Reddie@ca.com>]

  *) Make mkdef.pl parse some of the ASN1 macros and add apropriate
     entries for variables.
     [Steve Henson]

  *) Fix a deadlock in CRYPTO_mem_leaks().
     [Bodo Moeller]

  *) Add functionality to apps/openssl.c for detecting locking
     problems: As the program is single-threaded, all we have
     to do is register a locking callback using an array for
     storing which locks are currently held by the program.
     [Bodo Moeller]

  *) Use a lock around the call to CRYPTO_get_ex_new_index() in
     SSL_get_ex_data_X509_STORE_idx(), which is used in
     ssl_verify_cert_chain() and thus can be called at any time
     during TLS/SSL handshakes so that thread-safety is essential.
     Unfortunately, the ex_data design is not at all suited
     for multi-threaded use, so it probably should be abolished.
     [Bodo Moeller]

  *) Added Broadcom "ubsec" ENGINE to OpenSSL.
     [Broadcom, tweaked and integrated by Geoff Thorpe]

  *) Move common extension printing code to new function
     X509V3_print_extensions(). Reorganise OCSP print routines and
     implement some needed OCSP ASN1 functions. Add OCSP extensions.
     [Steve Henson]

  *) New function X509_signature_print() to remove duplication in some
     print routines.
     [Steve Henson]

  *) Add a special meaning when SET OF and SEQUENCE OF flags are both
     set (this was treated exactly the same as SET OF previously). This
     is used to reorder the STACK representing the structure to match the
     encoding. This will be used to get round a problem where a PKCS7
     structure which was signed could not be verified because the STACK
     order did not reflect the encoded order.
     [Steve Henson]

  *) Reimplement the OCSP ASN1 module using the new code.
     [Steve Henson]

  *) Update the X509V3 code to permit the use of an ASN1_ITEM structure
     for its ASN1 operations. The old style function pointers still exist
     for now but they will eventually go away.
     [Steve Henson]

  *) Merge in replacement ASN1 code from the ASN1 branch. This almost
     completely replaces the old ASN1 functionality with a table driven
     encoder and decoder which interprets an ASN1_ITEM structure describing
     the ASN1 module. Compatibility with the existing ASN1 API (i2d,d2i) is
     largely maintained. Almost all of the old asn1_mac.h macro based ASN1
     has also been converted to the new form.
     [Steve Henson]

  *) Change BN_mod_exp_recp so that negative moduli are tolerated
     (the sign is ignored).  Similarly, ignore the sign in BN_MONT_CTX_set
     so that BN_mod_exp_mont and BN_mod_exp_mont_word work
     for negative moduli.
     [Bodo Moeller]

  *) Fix BN_uadd and BN_usub: Always return non-negative results instead
     of not touching the result's sign bit.
     [Bodo Moeller]

  *) BN_div bugfix: If the result is 0, the sign (res->neg) must not be
     set.
     [Bodo Moeller]

  *) Changed the LHASH code to use prototypes for callbacks, and created
     macros to declare and implement thin (optionally static) functions
     that provide type-safety and avoid function pointer casting for the
     type-specific callbacks.
     [Geoff Thorpe]

  *) Use better test patterns in bntest.